Palaeosauriscus is a name that has been given to several different genera of reptiles between 1843 and 1959.
Palaeosauriscus fraserianus, described by Edward Drinker Cope in 1878,[1] is a nomen dubium included with Anchisaurus polyzelus. P. diagnosticus (von Huene, 1932/Kuhn, 1959) is a juvenile Sellosaurus. "P. sternbergii" (Fitzinger, 1843) is a nomen nudum probably synonymous with Palaeosaurus sternbergii. It is probably crocodilian.
None of these species are considered valid today, as all the material has been assigned to other genera, leaving Palaeosauriscus an invalid genus.
Riley, H., and S. Stutchbury, 1836, "A description of various fossil remains of three distinct saurian animals discovered in the autumn of 1834, in the Magnesian Conglomerate on Durdham Down, near Bristol", Proceedings of the Geological Society of London 2:397–399